Nielsen, jr
bits for pipe punches

ABSTRACT

A PUNCH T WELDED TO A GAS MAIN. SCREW-THREADEDLY ENGAGED WITH THE INSIDE OF THE T IS AN ELONGATED PUNCHING BIT HAVING A SOCKET PORTION AT ONE END FOR RECEIVING AN EXTENSION SHAFT OF A RATCHET WRENCH WHICH ROTATES AND FEEDS THE BIT INTO THE GAS MAIN. THE PUNCHING BIT FORMS THE HOLE IN THE GAS MAIN BY MEANS OF A HOLLOW PUNCHING END FORMED AS A CAM WITH TWO LOBES ON THE ENDOPPOSITE THE SOCKET PORTION. AXIALLY SPACED FROM THE PUNCHING END IS A SECOND CAM OF LARGER DIAMETER ALSO HAVING TWO LOBES FOR ENLARGING THE PUNCHED HOLE BY A SWAGING CTION. A BEVELED PORTION OF LARGER DIAMETER THAN THE SECOND CAM AND SPACED AXIALLY FURTHER IN FROM THE PUNCHING END THAN THE SECOND CAM SERVES AS A VALVE FOR SHUTTING OFF THE FLOW OF THE GAS VIA THE T. THE PUNCHING BIT FORMS THE HOLE AND ENLARGES IT BY A PUNCHING AND SWAGING ACTION AS OPPOSED TO A CUTTING-BY-CHIP-REMOVAL ACTION. THE THUS PUNCHED COUPON OR SLUG WORKS ITS WAY INTO THE BORE OF THE HOLLOW PUNCH END BY COLD FLOW OF THE METAL AND IS PACKED SO TIGHTLY IN THE BORE THAT IT IS RETAINED WITH CERTAINTY.

y 1972 J. NIELSEN, JR

BITS FOR PIPE PUNCHES Original Filed June 24, 1966 2 Sheets-Sheet 113282822302 flazifiew J. .zvazezsea, J34. 3y WK W,

July 11, 1972 NIELSE JR Re. 27,431

BITS FOR PIPE PUNGHES Original Filed June 24. 196E 2 Sheets-Sheet 2Fig.4. 9 5

y WKW United States Patent 27,431 BITS FOR PIPE PUNCHES Anker J.Nielsen, Jr., Holden, Mass., assignor to M. B. Skinner Company, Divisionof Textron Inc. Original No. 3,411,527, dated Nov. 19, 1968 Ser. No.560,209, June 24, 1966. Application for reissue Dec.

2 1970 Ser.No.94 638 rm. (:1. Bi 41/08; Fl6e 41/04 US. Cl. 137-318 32Claims Matter enclosed in heavy brackets I appears in the originalpatent but forms no part of this reissue specification; matter printedin italics indicates the additions made by reissue.

ABSTRACT OF THE DISGLOSURE 'for enlarging the punched hole by a swagingaction. A

beveled portion of larger diameter than the second cam and spacedaxially further in from the punching end than the second cam serves as avalve for shutting olf the flow of the gas via the T. The punching bitforms the hole and enlarges it by a punching and swaging action asopposed to a cutting-by-chip-removal action. The thus punched coupon orslug works its way into the bore of the hollow punch end by cold flow ofthe metal and is packed so tightly in the bore that it is retained withcertainty.

The present invention comprises a punching member or bit for use in apunching device or tool of known construction for tapping a gas main,such tool having the form of a T, one leg of which is welded or clampedto an existing gas main in radial relation, to serve first as a screwpress punching a hole in the main, and thereafter remaining as aconnection or valve admitting gas to a service pipe joined thereto andconducting the gas to the .point of its utilization. The punching memberor bit is fixed in the end of an arbor which is in screw-threadedengagement with the interior bore of the opposite end of the T from thatwhich is welded to the main, and the bit is forced through the wall ofthe main by being advanced and rotated by the arbor as the latter isrotated manually through a wrench applied to the arbor.

Since prior devices have needed a very considerable muscular effort todrive the punch cold through the heavy wall of a steel gas main, withthe available leverage curtailed by the limitation on the size of theaccess excavation dictated by economy of labor, a leading object of thepresent invention has been to make the bit penetrate the main with theexpenditure of much less physical elfort than required hitherto.

A further object of the invention is to insure the retention by the bitof the slug punched out of the wall of the main in forming the new gasoutlet, and to make ice possible its retraction completely out of themain and T if desired.

Another object ofthe invention is to form the plowing, kneading, orcold-flow inducing parts of the bit so as to possess sufficient bulk ofthe component metal stock to resist rounding over and dulling under theintense pressure to which they are subjected in use.

It is an additional object of the invention to devise a bit attainingthe foregoing aims economically through admitting of its manufacture byautomatic machines and with a minimum of operations.

Other objects of the invention, and the manner of their attainment, aremade plain as described hereinafter and as set forth in the claimsappended hereto.

An illustrative embodiment of the invention is shown in the accompanyingdrawings, in which FIG. 1 is an elevation in axial section of a punch Twelded to a gas main, with the novel bit in place in the arbor, and aratchet wrench and extension shaft in place in the socket of the arbor,ready for use.

FIG. 2 is a similar view showing the relation of the parts after the bithas formed the hole or port in the gas mam.

FIG. 3 is a similar view showing the arbor and bit retracted to open theport formed in the main, with the wrench removed, the leg capped and theslug retained in the bit.

FIG. 4 is an enlarged side elevation of the bit in place in the socketformed for it in the arbor, the latter being in section.

FIG. 5 is a view similar to FIG. 4, which the bit rotated from theposition in FIG. 47

FIG. 6 is an end view of the working end of the bit, still furtherenlarged.

The punch T 1, FIGS. 1-3, is mainly of known construction and form,having one leg 3 welded to the gas main 7 by the head 5. The oppositeend 9 is threaded internally at 11, with a fine thread such as 20 turnsto the inch, to receive the correspondingly threaded portion 13 of thearbor 15, the latter having a hexagonal socket 17 in the upper end forthe reception of the extension shaft 21 of a ratchet wrench 23.

In the arbors lower end is formed a fluted socket 19 in which ispress-fitted the knurled tang 25 of thenovel bit 27, the shoulder 29 ofthe bits enlarged portion 31 seating against the end of the arbor. Thearbor feeds the bit into the wall of the main 7 as the arbor is advancedby screw thread 11.

The working end of the bit 27 is part tubular, being recessed as shownat 33, and the extreme end-portion 35 is formed as a cylindrical camwith two lobes forming apices 37 diametrically apart from each other,each preferably extending raidally inward, at right angles to the axisof the recess. The slopes of the two sides of each lobe meet at the apex37 to form a sharp dihedral angle, and the end face is at right anglesto the bits axis all the way around, even though it has a rise and fallin an axial direction. Though the peaks 37 are clearly and sharplyangular, the valleys 39 are preferably formed on a radius, and hencerounded in side vie-w (FIG. 5).

The end portion 35 performs the initial break-through in the wall of themain 7, and thus may be termed the pilot. The unique formation of itsworking face just described has the novel action of producing cold flowof the metal of the main, first laterally out of the path of apices 37till resistance-builds up" and then'onward in the cir- :ular path ofthese apices 37 by a species of kneading and lifting action caused bythe alteration of peaks and hollows as the bit revolves and bores deeperinto the metal. The divergence of the forcesthe resultant of the pres-;ures radially and axially of the bitwithin the metal of the mainultimately breaks loose a mushroom-shaped slug 40 with a shank wedged inthe bore 33 and a head wider than the diameter of the pilot 35.

The outside wall of the ,pilot 35 is tapered, with the larger endadjacent to the cams 37, 39. Thus the pilot rotates with minimumfriction in the hole it forms in the main 7.

The 'body portion 41 of the bit is of materially larger iiarneter thanthe pilot, and joins it with a taper of around [8 formed with cam lobes43 which parallel the contour of the face of the piloti.e. with peak andvalley in ahase with those of the pilots face. These symmetricallyleveloped lobes form sharp dihedral angles 45 in planes ntersecting thebits axis. When this portion of the bit is "orced into the hole made bythe pilot the hole is enlarged ;o a diameter exceeding that of the headof the mushroom- ;haped ring 40 permitting it to be withdrawn throughthe 1ole 47 thus punched in the main, and if desired remo'ved :ntirelyfrom the T. Like the pilot, the body 41 is tapered feversely to reducefriction, once it passes through the role.

The kneading action of the high pointspeaks45 of be 18 tapered portion43 diverts or swages the metal of he main inwardly of the latter andlaterally of the hole l7. Since there is no cutting action by either theapices W or 45, there are no chips or shavings to fall into the nain 7or get into the service pipe line. All metal removed from the main iscomprised within the slug 40, and is pernanently retained in the bit 27.

The mouth of the bore 33 in the bit is chamfered slighty at 48; thiscauses the stem of the slug to be a tight fit n the bore because thechamfer swages the metal of the tem into the bore, packing it in sotightly that it is reained with certainty. Otherwise, with a straightcylinlrical bore the stern of the slug is apt to be formed with llesser'diameter than the bore, especially if there is any :ccentricityof the arbor when rotated; then it will not be etained.

The advantage of making the surfaces which induce cold low, or swaging,diverting, kneading, or plowing action, is cam lobes creating sharpdihedral angles but not cuting edges, is the greatly reduced torqueloadthe markdly greater ease of driving the punch through the main vall7. The peaks are backed up by ample amounts of olid metal and have onlya gradual slope, so that they .0 not dull or blunt or round over beforethe punching completed.

The parts will normally stand in the relation shown in IG. 3 when inuse, with the newly formed port 47 in the as main open, a suitableservice pipe attached to the ateral outlet 49 of the T, and a pipe cap51 on the end hrough which the wrench was applied. However, as hown inFIG. 2, the beveled shoulder 53 of greater radial xtent than the secondcam will serve to close the port 7 when flow of gas via the T is to beshut off for any :ason, the punch T thus performing as a valve.

While I have illustrated and described one form in 'hich the inventionmay be embodied, I am aware that [any modifications may be made thereinby any person killed in the art, without departing from the scope of tieinvention as expressed in the claims. Therefore, I do ot wish to belimited to the particular form shown, or the details of constructionthereof, but what I do claim 1. A bit for a pipe punch having a bodyportion wherey to rotate it and a part-tubular end portion formed withcam on its open end having a plurality of lobes forming ihedral anglesat their apices and with a second cam I intermediate the length of thisend portion in axially spaced'relation to the first cam and of greaterradial extent than the first cam.

2. A bit according to claim 1 in which the outside wall of the endportion is of lesser diameter adjacent the second cam than at the endcam.

3. A bit according to claim 2 in which the outside wall is taperedre-versely between the said two cams.

4. A bit according to claim 1 in which the second cam is formed on ataper.

5. A bit according to claim 1 in which the end cam has two lobes formingsharp dihedral angles located diametrically apart.

6. A bit according'to claim 5 in which the apices forming dihedralangles are aligned with each other.

7. A bit according to claim 6 in which theapices extend radially inward.g

8. A bit according to claim 1 in which the end face is at right anglesto the bits axis throughout the entire circuit of the end face.

9. A bit according to claim 5 in which the intervals between the apicesof the lobes are of curving contour throughout.

10. A bit according to claim 1 in which the second cam has a pluralityof lobes forming dihedral angles at their apices.

11. A bit according to claim 1 in which the body portion has a beveledshoulder of greater radial extent than the second cam.

12. A bit according to claim 1 in which the mouth of the bore of thetubular end is chamfered.

13.,A lapping punch for metal pipe and for forming therefrom andretaining a slug with certainty, said punch having a metal bit with abody portion whereby to rotate it and a part-tubular, open working endportion with a bore for retaining with certainty a slug formed from themetal pipe tapped by the bit, said bit being formed with a first camportion on its open end having a plurality of swaging lobes formingdihedral angles at their apices, .a

second camportion positioned in axially spaced relation to the first camportion and intermediate the length of said end portion and being ofgreater radial extent than the first cam portion, the second cam portionbeing tapered and having at least one lobe forming a dihedral angle atits apex and having an external cross-sectional size and shapesufiicient to form an openingthat is larger than that swaged by thefirst cam portion, said second cam portion being axially spaced andseparated rearwardly of the mouth of the bore and apices of the firstcam portion so as to swage the sides of the opening in a pipe beingpunched sufiiciently large to permit a slug held in said bore, whichslug is smaller in cross-section than the opening after being swaged bythe second cam portion, to be withdrawn with certainty with the punchthrough the swaged opening.

14. The punch of claim 13 in which said end portion of the bit betweenthe lobes of the first cam portion and the second tapered cam portion istapered reversely.

15. The punch of claim 13 in which the bit has a tapered shoulder ofgreater radial extent than and positioned'rearwardly of the secondcamportion, which tapered shoulder serves to close and open the swagedopening when the punch is advanced and retracted.

16. The punch of claim 15 in which the bit is tapered reversely betweenthe second cam portion and tapered shoulder.

17. A tapping punch for metal pipe and for forming therefrom andretaining a slug with certainty, said punch having a bit with a bodyportion whereby torolale it and a part-tubular, open, working endportion with a bore for retaining with certainty a slug formed from themetal pipe tapped by the bit, said slug having, upon being formed, ahead portion and a shank portion extending therefrom, said head portionof the slug being of a :larger, cross-sectional size than said bore andsaid shank being of a crosssectional size substantially conforming tothat of the bore,

. said bit being formed witha first cam portion on its open end having aplurality of swaginglobes forming dihedral ;i ntermediate the lengthofsaid end portion and being of gneaterradial extent than the first camportion, the second carn;por t i o n being tapered and having anexternalcrosssectional size and shape suflicient to form intentionally anopening thatis larger than both the opening swaged by the first camportion and the head portion .of the slug, said second cam portionbeing"axially spaced "and separated refarwardly of the mouth of the boreand apices of the first cam portion so as to swage the sides of theopening in apipe being punched sufliciently large to permit a slug heldin said bore, which head portion of the slag is larger in cross-sectionthan the opening swaged by said first cam portion and smaller incross-section than the opening after being swaged by the second camportion, to be withdrawn with certainty with the punch through theswaged opening.

18. The punch of claim 17 in which said end portion of the between thelobes of the first cam portion and the second tapered cam portion istapered reversely.

19. The punch of claim 17 in which said second cam portion hasanon-circular external cross sectional shape normal to: the axis of thebit.

20. The punch of claim 17 in which said second cam portion has aplurality of lobes forming dihedral angles at their apices.

21. The punch of claim 17 in which the bit has a tapered shoulder ofgreater radial extent than and positioned rearwardly of the second camportion, which tapered shoulder serves to close and open the swagedopening when the punch is advanced and retracted.

22. The punch of claim 21 in which the bit is tapered reversely betweenthe second cam portion and tapered shoulder. 1

23. A slug-retaining, pipe tapping assembly for tapping an opening in ametal walled pipe comprising:

a punch T adapted to be secured in radial relation to a metal pipe to betapped, said T having a longitudinally extending leg adapted to besecured to the pipe at the inner end of said leg and having internalthreads at the other, outer end of said leg, said T having a laterallyextending outlet intermediate said ends of the leg, said outlet beingadapted to be attached to a service pzpe;

a longitudinally extending tapping punch for metal pipe and for formingtherefrom and retaining a slug with certainty, said punch having threadsat its outer end adapted to threadably engage said internal threads atthe outer end of the leg of the T and to permit axial advancement ofsaid punch upon rotation into said pipe to be tapped and withdrawaltherefrom upon reverse rotation;

said punch having a metal bit with a body portion whereby to rotate itand a part-tubular, open, inner working end portion with a bore forretaining with certainty a slug formed from the metal pipe tapped by thebit, said bit being formed with a first cam portion on its open endhaving a plurality of swaging lobes forming dihedral angles at theirapices, a second cam portion positioned in axially spaced relation tothe first cam portion and intermediate the length of said end portionand being of greater radial extent than the first cam portion, thesecond cam portion being tapered and having at least one lobe forming adihedral angle at its apex and having an external cross-sectional sizeand shape sufiicient to form intentionally an opening that is largerthan that swaged by the first cam portion, said second cam portion beingaxially spaced and separated rearwardly of the mouth of the bore andapices of the first cam portion so as to swage the sides of the openingin a pipe j being punched sufliciently large to permit a slugheldinsaidbore, which slug is smaller in cross-section than the "opening after'being swaged by the second cam portion," to be withdrawn with certaintywith the punch through the swaged openmg. 24, The slug-retaining,pipetapping assembly of claim 25' in which said end portion of the bitbetween the lobes of the first cam portion and the second tapered camportion is tapered reversely;

"25. The slug-retaining, pipe tapping assemblyof claim 23 in which thebit has a tapered shoulder of greater radial extent than and positionedrearwardly of the second cam portion,]which tapered shoulder serves toclose and open the swaged opening when the punch is advanced retracted.2 6. The slug-retaining, pipe tapping assembly of claim 25 in which thebit is tapered reversely between the second cam portion and taperedshoulder.

27. A slug-retaining, pipe tapping assembly for tapping 'n in ametalwalled pipe comprising: d T adapted to be secured in radial relation toa metal pipe to be tapped, said T having a longztudtnally extending legadapted to be secured to the pipe at the inner end of said leg andhaving internal threads at the other, outer end of said leg, said Thaving a laterally extending outlet intermediate said ends of the leg,said outlet being adapted to be attached to a service pipe;

a longitudinally extending tapping punchfor metal pipe and for formingtherefrom and retaining a slug with certainty, said punch having threadsat zts outer end adapted to threadably engage said internal threads atthe outer end of the leg of the T and to permit axial advancement ofsaid punch upon rotation into said pipe to be tapped and withdrawaltherefrom upon reverse rotation;

said punch having a bit with a body portion whereby to rotate it and apart-tubular, open inner worl zng end portion'with a bore for retainingwith certainty a slug formed from the metal pipe tapped by the bit, saidslug having, upon being formed, a head portion and a shank portionextending therefrom, said head portion of the slug being of a largercross-sectional size substantially conforming to that of the bore, saidbit being formed with a first cam portion on its open end having aplurality of swaging lobes formrng dihedral angles at their apices, asecond cam portion ositioned in axially spaced relation to the first camportion and intermediate the length of said end portion and being ofgreater radial extent than the first cam portion, the second cam portionbeing tapered and having an external cross-sectional size and shapesufficient to form intentionally an opening that is larger than both theopening swaged by the first cam portion and the head portion of theslug, said second cam portion being axially spaced and separatedrearwardly of the mouth of the bore and apices of the first cam portionso as to swage the sides of the opening in a pipe being punchedsufliciently large to permit a slug held in said bore, which headportion. of the slug is larger in cross-section than the opening swagedby said first cam portion and smaller in crosssection than the openingafter being swaged by the second cam portion, to be withdrawn withcertainty with the punch through the swaged opening.

28. The slug-retaining, pipe tapping assembly of claim 27 in which saidend portion of the bit between the lobes of the first cam portion andthe second tapered cam portion is tapered reversely.

29. The slug-retaining, pipe tapping assembly of claim 27 in which saidsecond cam portion of the bit has a noncircular external cross-sectionalshape normal to the axis of the bit.

30. The slug-retaining, pipe tapping assembly of claim 27 in which saidsecond cam portion of the bit has a plurality of labes forming dihedralangles at their opices.

.31. The slug-retaining, pipe tapping assembly of claim 27 in which thebit has diapered shoulder of greater radial extent than and positionedrearwardly of the second cam portion, which tapered shoulder serves toclose and open the swaged opening when the punch is advanced andretracted. I

32. The slug-retaining, pipe tapping assembly of claim 31 'in'which thebit is tapered reversely between the secand cam portion and taperedshoulder.

References Cited The following references, cited by the Examiner, are"of record in the patented file of this patent orfthe original M.'CARYNELSON, Primary Examiner D. R. MATTHEWS, Assistant Examiner.

